Investigation On The Effectiveness Of Negative Pressure Wound Therapy:the Meta-analysis And Clinical Retrospective Study

Background:Negative pressure wound therapy, also known as topical negative pressure (TNP) or vacuum-assisted closure (VAC) therapy, is new emerging therapy mode which was used to encourage wound healing. It is used both as primary treatment of chronic and complex wounds and as an adjunct for temporary closure and wound bed preparation preceding surgical procedures such as skin grafts and flap surgery. The device has come into wide and successful use, although the physiological basis of its effect is not yet fully understood, and with a delay, increasingly evidence-based data become available.Objective:These studie includes three parts. The fisrt part of this study involving experimental research reveals the HO-1concentration and expression level in the trauma tissue. The second part of this study is a cohort study which explored the effectiveness of negative pressure wound therapy in various wound condition in the author’s hospital. The last part of this study is a meta-analysis which unvealed the up-to-date evidence in the filed of NPWT therapy..Methods:This research contains three parts. In part1, wound tissues were collected from8chronic wound patients. RT-PCR detection was applied to reveal the expression levele of HO-1mRNA in various time spot. Western-Blot method was introduced to show the concentration of HO-1protein. In part2, a cohort study was conducted. Comparision was made between those received NPWT treatment and those who received traditional dress changing treatment. The data were analysised with SPSS19.00software, In part three, a meta-analysis was made from peer-reviewed publications (Cochran library, Embase, PubMed-Medline and Chinese BioMedical Literature Database) chosen on the basis of inclusion of the terms "suction, vacuum, fasciitis, wound healing, skin ulcer, diabetic foot". Scientific data were evaluated from randomized clinical trials, observations of clinical applications, and case reports. The data were processed with RevMan software.Results:The HO-1mRNA expression in the wound tissue was found increased after NPWT treatment. The HO-1protein titre from the negative therapy group was inceased correspondingly. There was no statistically significant values observed in the traditional therapy group regarding the level of HO-1mRNA expression and HO-1protein titre. In part2,57cases were found with the primarily search strategy.25cases were treated with NPWT therapy, while20cases were treated with traditional methods. The other12patients were excluded from this study because they cannot be followed to the end point. Data analysis showed positive efficacy of NPWT therapy on terms of wound granulation and pre-operation preparing period. But there is no statistic significance when comparing the bacteria counting and therapy cost between these two methods.In part three, totally1756publications were find with the primarily search strategy.447publications meets the including criteria.267publications were further excluded because they meets the excluding criteria. After roughly reading of the rest publications, only22papers were kept while the other158reviews were discarded. By intensive reading, only15papers were finally preserved. Systematic analysis of the data shows efficacy concerning diabetic foot therapy, reducing wound area, promoting wound granulation, and shorting the operation-preparing period. In respect to wound healing period, NPWT shows no significant beneficial effect comparing with conventional wound therapy. NPWT have no obvious advantages over traditional therapy in chronic wound treatment, In acute wound therapy, the NPWT therapy will play a more important role.Conclusions:NPWT therapy will increase HO-1mRNA expression and raise HO-1protein level in local tissue. This may be part of the reasons which NPWT promote the wound healing. Results of Meta-analysis showed that there is a lack of good quality RCTs to evaluate NTWT as a treatment for chronic wounds. It will be more beneficial when applied in acute circumstances. NPWT promote granulation growth and short operative preparing period. NPWT therapy when used indicated will proved to be an excellent tool for plastic surgeon to promote wound healing.